Adjustable auger.



No. 796,182. 'PAIENTED AUG. 1, 1905 A. G. BOHLIN. ADJUSTABLE AUGER.

AYPLIOAIION FILED J'AR'J, 1905.

%HI eooap UNITED STATES PATENT oFFIon.

Specification of Letters Patent,

Patented Aug. 1, 1905.

Application filed January 7, 1905. Serial No. 240,024.

Figure 1 is an elevation of my improved ad justable auger complete, and Fig. 2 is an elevation with a part in vertical section.

A represents the shaft of the tool, having the handle-connecting shank b of the upper end and the gimlet-point c of the lower end and the short fixed radial boring-bit d at the junction of the base of the gimlet-point with the end of the shaft. For the application of the extensible bit 6 I provide a mortise f di ametrically through the lower end portion f of the shaftjust above the junction of the gimlet-point 0, said end portion of the shaft preferably being a little larger in diameter than the rest of the shaft, 'above which enlargement is a screw-threaded section g, whereon a clamping-nut h is threaded for screwing up and down freely, said nut having an expanded socket 2 on the lower side of suitable internal diameter to slip down over end portion f to some extent belowv the upper portion of mor-- tise f, and I construct said expansible bit e with a shank j, to which said bit is connected near one end by a web 70, with a parallel space Z between the rear edge of the bit, enabling said shank to be inserted in the slot, so as to be shifted along from one position to another, with the back edge of the bit bearing against the surface of a flattened portion of part f at m for support against the resistance of the work on the bit 6. The nut h is when the bit is set in the desired position readily screwed down onto shank j to bind it fast.

It will be seen that the shaft is much stronger with theslot for reception of the shank of the bit 6 than when a notchis made in the side of the shaft, which necessitates cutting away considerably more than one-half of the metal, and the clamping-nut affords the means, by

the flat-sided part m, for the use of a wrench in tightening it, by which it can be tightened more securely than can be effected 'witha setscrew operated by a screw-driver in the common way.

What I claim as my invention is 1. In an extensible auger, the combination with the shaft having a transverse slot above and in proximity to the gimlet-point, of the adjustable bit having the shank traversing said slot and the cutting portion connected with the shank by a web leaving a clearancespace between the shank and cutting portion permitting lateral adjustment of the bit, and the clamping-nut on the shaft above the bitshank adapted to clamp said shank for securing the bit, substantially as shown and described. 2. In an adjustable auger, the combination with the shaft havinga transverse slot above and in proximity to the gimlet-point, of the adjustable bit having the shank traversing said slot with a clearance-space between said shank and the cutting portion of the bit permitting lateral adjustment of the bit, and the clamping-nut on the shaft above the bit-shank and adapted to clamp said shank for securing ALEXANDER C. BOHLIN.

Witnesses:

C. SEDewIoK, J. M. HOWARD. 

